1. Field of the Invention
This invention relates to apparatus for marking a workpiece, and more particularly, to a single wheel billet marker movable through an arcuate path into and out of a stamping position and moved from the stamping position to impress a mark on a billet where the marking wheel is also advanced by a frame, movable transversely relative to the arcuate path of the marking wheel through an increment of steps and thereafter rapidly returned to the original marking position for marking the next billet.
2. Description of the Prior Art
In the marking of billets, slabs, bars, ingots, or the like, it is known to impress a series of characters on the face of the workpiece by a single wheel marker that includes a marking wheel having a plurality of marking characters or elements on the peripheral surface thereof. An example single wheel marker is illustrated and described in U.S. Pat. No. 4,214,520. Similar devices are also provided in which a marking head includes a plurality of marking wheels for marking rolled stock and the like, such as disclosed in U.S. Pat. Nos. 3,306,186; 3,541,954; and 3,636,871.
With both single and multiple marking wheel markers, the respective marking wheel is rotated until the desired character on the wheel periphery is in marking position. The wheel is held in position by a suitable locking device, and thereafter, an actuator is remotely actuated to move the marking wheel to strike the billet and impress the selected character thereon. Thereafter, the marking wheel is retracted and the wheel incrementally rotated and moved laterally to the next position for marking the billet. The actuator is sequentially operated to move the marking head so that the character is stamped on the surface of the billet. This operation is repeated through the required sequence of steps to impress a series of marks on the billet.
Once the billet has been marked, the next billet must be moved into position for marking. This requires the marking head to be withdrawn to facilitate the movement of the next billet into position as rapidly as possible so that a number of billets can be marked in rapid succession. To accomplish this the marking wheel, following the marking of a billet, must be moved to a position to facilitate efficient movement of the next billet into position. If the marking wheel cannot be rapidly moved to a convenient location to facilitate the replacement of a marked billet with an unmarked billet, the marking operation is delayed.
It is also the practice, particularly with single wheel markers, to incrementally, laterally move the marking wheel opposite the billet face to stamp the face with a series of marking characters. During the marking operation, this is accomplished automatically in a sequence of steps which include moving the marking wheel to stamp the billet and rotating the marking wheel to place the next desired character in marking position. Once the desired series of characters has been impressed on the billet by incremental lateral movement of the marking wheel it is necessary to return the marking wheel to the initial marking position for marking the next billet. If the marking wheel has been incrementally advanced by the operation of an indexing ratchet, then movement of the wheel is not continuous. To incrementally return the marking head to the initial position is undesirable because it delays the marking of a succession of billets which follow one after another.
Therefore, there is need to provide, in a single wheel marker, apparatus for quickly raising and lowering the marking wheel into the position opposite the billet for marking and, after the incremental lateral advancement of the marking wheel provide rapid return of the marking wheel to the initial position after the desired series of characters have been impressed on a billet.